Pencil sharpener



FIG. 1 is a front elevational view of a pencil sharpener showing my new design; the rear elevational view being a mirror image of the front elevational view;

FIG. 2 is a left side view thereof; the right side view being a mirror image of the left side view;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a bottom plan view thereof.

The broken line showing portions of the pencil sharpener are included for information purposes only and form no part of the claimed design. 

The ornamental design for a pencil sharpener, as shown and described. 